• Journal of Animal Science and Technology
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• v.65 no.3
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• pp.596-610
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• 2023

Focusing high marble deposition, Hanwoo feedlot system uses high-energy diet over the prolonged fattening period. However, due to the individual genetic variation, around 40% of them are graded into inferior quality grades (QG), despite they utilized the same resources. Therefore, focusing on development of a nutrigenomic based precision management model, this study was to evaluated the response to the divergent selection on genetic merit for marbling score (MS), under different dietary total digestible nutrient (TDN) levels. Total of 111 calves were genotyped and initially grouped according to estimated breeding value (high and low) for marbling score (MS-EBV). Subsequently, managed under two levels of feed TDN%, over the calf period, early, middle, and final fattening periods following 2 × 2 factorial arrangement. Carcasses were evaluated for MS, Back fat thickness (BFT) and Korean beef quality grading standard. As the direct response to the selection was significant, the results confirmed the importance of initial genetic grouping of Hanwoo steers for MS-EBV. However, dietary TDN level did not show an effect (p > 0.05) on the MS. Furthermore, no genetic-by-nutrition interaction for MS (p > 0.05) was also observed. The present results showed no correlation response on BFT (p > 0.05), which indicates that the selection based on MS-EBV can be used to enhance the MS without undesirable effect on BFT. Ultimate turnover of the Hanwoo feedlot operation is primarily determined by the QGs. The present model shows that the initial grouping for MS-EBV increased the proportion of carcasses graded for higher QGs (QG1⁺⁺ and QG1⁺) by approximately 20%. Moreover, there appear to be a potential to increase the proportion of QG 1⁺⁺ animals among the high-genetic group by further increasing the dietary energy content. Overall, this precision management strategy suggests the importance of adopting an MS based initial genetic grouping system for Hanwoo steers with a subsequent divergent management based on dietary energy level.

• Journal of Embryo Transfer
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• v.19 no.3
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• pp.239-244
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• 2004

The present study was to investigate the pregnancy rate, gestation length and abortion rate of the recipients which transferred blastocysts produced by in-vivo collection, in-vitro fertilization (IVF) and nuclear transfer (NT). In addition, we investigate the birth weight and survival rate of the calves derived from the same methods. The pregnancy rate was 56.3％ in-vivo blastocysts, significantly higher than 19.4％ in NT blastocysts (p<0.05) but not significantly different from 30.0％ in IVF blastocysts. The abortion rate and the gestation length did not differ among the treatment groups (abortion rate: 0, 22.2 and 16.7％ respectively; gestation length: 278.8, 289.4 and 281.4 days respectively). The mean birth weight was significantly higher in NT calves (39.9kg) than in-vivo calves (25.5kg p<0.05). Recipients of in-vivo blastocysts (n=9) had all normal delivery and all of their calves survived on the 60$^{th}$ day from the birth. Recipients of IVF blastocysts (n=7) had all normal delivery but one of their calves died on the 48$^{th}$ day from the birth. Among recipients of NT blastocysts (n=5), three had normal delivery and two had Caesarean section. Among calves born through normal delivery (n=3) two died just after delivery but those born through Caesarean section all survived on the 60th day from the birth.

• Korean Journal of Organic Agriculture
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• v.31 no.4
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• pp.469-477
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• 2023

Animal welfare has been gradually gathering more attention from consumers over time, making it increasingly important to assess the level of stress experienced by livestock. Traditionally, stress has been measured by collecting blood to assess cortisol levels, an action that can be considered distressing for the animal. Therefore, we aimed to explore the feasibility of using hair as an alternative medium to blood for stress assessment. We utilized B/F (blood collected at the farm), B/A (blood collected after transport to the auction), and H/A (hair collected at the auction after blood sampling) from calves at the age of 7-9 months transported from the farm to the auction. Hair underwent a washing and extraction process to utilize hair extracts, while blood was centrifuged to analyze using ELISA. The cortisol concentration in the blood was significantly higher in B/A compared to B/F (p<0.05), confirming that the calves experienced stress during transportation. Additionally, H/A was significantly lower than both B/A and B/F (p<0.0001). These results emphasized that cortisol in hair is not suitable for investigating short-term stress in livestock, as it is with blood. While measuring stress indices using hair may not be appropriate for replacing blood, it is considered a highly suitable practice for animal welfare, and further research in this area should be continued.

• Journal of Animal Science and Technology
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• v.48 no.2
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• pp.247-254
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• 2006

The present study was carried out to determine the effects of feeding levels of barley grain in diets of Hanwoo on the growth performance and carcass characteristics of Hanwoo. Twenty Hanwoo bull calves (initial mean body wt. 99kg) were randomly divided to examine the effects of 5 feeding levels of barley grains(addition levels: 0, 0 and 40% for FII40; 0, 0 and 60% for FII60; 0, 20 and 40% for F2040; and 0, 20 and 60% for F2060 during the growing, early fattening and late fattening periods, respectively) on growth performance and meat quality. Body weight was not affected by the feeding level of barley grains through the whole experimental period, although the body weight of Hanwoo bulls fed FII40 diet at 24 months old of age tended to be lower(591.5kg) than that of other animals(606.2～614.6kg). However, body weight gain in the bulls of the FII60 diet was slightly increased(P<.19). The feeding levels of barley grains did not influence on fasting body weight, carcass weight, carcass rate, lean meat, retailed cut, KPH fat and bone yield. The lean meat yield(89.82%) and fat yield(20.28%) tended to increase in Hanwoo bulls fed the F2060 compared with other treatments. Feeding of the diets of FII40 resulted in the higher marbling scores as 3.75, respectively than other diets.

• Animal Bioscience
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• v.35 no.11
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• pp.1808-1816
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• 2022

Objective: The study of Hanwoo (Korean native cattle) has mainly been focused on meat quality and productivity. Recently the field of microbiome research has increased dramatically. However, the information on the microbiome in Hanwoo is still insufficient, especially relationship between vagina and feces. Therefore, the purpose of this study is to examine the microbial community characteristics by analyzing the 16S rRNA sequencing data of Hanwoo vagina and feces, as well as to confirm the difference and correlation between vaginal and fecal microorganisms. As a result, the goal is to investigate if fecal microbiome can be used to predict vaginal microbiome. Methods: A total of 31 clinically healthy Hanwoo that delivered healthy calves more than once in Cheongju, South Korea were enrolled in this study. During the breeding season, we collected vaginal and fecal samples and sequenced the microbial 16S rRNA genes V3-V4 hypervariable regions from microbial DNA of samples. Results: The results revealed that the phylum-level microorganisms with the largest relative distribution were Firmicutes, Actinobacteria, Bacteroidetes, and Proteobacteria in the vagina, and Firmicutes, Bacteroidetes, and Spirochaetes in the feces, respectively. In the analysis of alpha, beta diversity, and effect size measurements (LefSe), the results showed significant differences between the vaginal and fecal samples. We also identified the function of these differentially abundant microorganisms by functional annotation analyses. But there is no significant correlation between vaginal and fecal microbiome. Conclusion: There is a significant difference between vaginal and fecal microbiome, but no significant correlation. Therefore, it is difficult to interrelate vaginal microbiome as fecal microbiome in Hanwoo. In a further study, it will be necessary to identify the genetic relationship of the entire microorganism between vagina and feces through the whole metagenome sequencing analysis and meta-transcriptome analysis to figure out their relationship.

• Journal of Animal Science and Technology
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• v.45 no.6
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• pp.997-1006
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• 2003

This study was conducted to investigate the national methane emission from livestock enteric fermentation. For methane emission estimation, livestock were mainly categorized to cattle, swine, poultry, sheep, goats and horses, and cattle were further sub-categorized to calves, fattening cattle, breeding cows in Hanwoo and calves, fattening cattle and lactating cows in dairy cattle. Tier 2 methane emission factors were deduced based on the characteristics of animal performances, live weight, slaughter weight, daily weight gain, and feed digestibility in each category. Tier 2 emission factors of Hanwoo range from 39 to 49 kg/head/year and it is similar to that of Tier 1(47kg/head/year). Tier 2 emission factor of dairy cattle was 107 kg/head/year and it is slightly lower than that of Tier 1(118kg/head/year). Total methane emission from livestock enteric fermentation by Tier 2 method was estimated to be 126.8 tones in 2001. The methane emissions by Hanwoo, dairy cattle, swine, goats, horses and sheep were 61.70, 47.76, 13.08, 2.25, 0.17 and 0.01 tones, respectively. By the use of Tier 2 method instead of Tier 1, the accuracy and reliability of methane emission estimates from livestock enteric fermentation in Korea is considered to be improved.

• Journal of Animal Science and Technology
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• v.48 no.6
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• pp.759-766
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• 2006

This study was conducted to investigate the genetic correlations among the traits used to select young bulls and proven bulls in Hanwoo Performance and Progeny Test Program in Korea. For the estimation of heritabilities and correlations among the growth traits of bulls and carcass traits of progeny steers, 2,532 records of performance tested bull calves and 1,819 records of progeny tested steers were collected from Livestock Improvement Main Center (LIMC), National Agricultural Cooperative Federation (NACF). Fixed effects of mixed model for each traits were selected by using stepwise regression analysis and prior values of variance components were estimated by MTDFREML. The prior values of variance components were estimated with pairwise 2 traits model followed by single trait analysis. The estimated heritability of backfat thickness(BF), dressing percentage(DP), loin-eye muscle area(LMA), marbling score(MS) and weight at 12 months(WT12) was 0.51, 0.32, 0.27, 0.33, 0.50 and 0.26, respectively. Genetic correlation of WT12 of bull calves with backfat thickness, carcass weight and loin-eye muscle area of steers was positive correlation as 0.05, 0.35 and 0.21, respectively. However genetic correlation of WT12 with DP and MS showed negative correlation as 󰠏0.09 and 󰠏0.27, respectively and these negative genetic correlations implies that bulls that may be superior in carcass traits can be lost at the first step of selection and current selection method should be modified to solve this problem.

• Journal of Microbiology and Biotechnology
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• v.19 no.5
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• pp.511-519
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• 2009

A chimeric gene encoding enhanced green fluorescent protein (EGFP) and a S-layer protein from Lactobacillus brevis KCTC3102, and/or two copies of the Fe-binding Z-domain, a synthetic analog of the B-domain of protein A, was constructed and expressed in Escherichia coli BL21(DE3). The S-layer fusion proteins produced in a 500-1 fermentor were likely to be stable in the range of pH 5 to 8 and $0^{\circ}C$ to $40^{\circ}C$. Their adhesive property enabled an easy and rapid immobilization of enzymes or antibodies on solid materials such as plastics, glass, sol-gel films, and intestinal epithelial cells. Owing to their affinity towards intestinal cells and immunoglobulin G, the S-layer fusion proteins enabled the adhesion of antibodies to human epithelial cells. In addition, feeding a mixture of the S-layer fusion proteins and antibodies against neonatal calf diarrhea (coronavirus, rotavirus, Escherichia coli, and Salmonella typhimurium) to Hanwoo calves resulted in 100% prevention of neonatal calf diarrhea syndrome (p<0.01), whereas feeding antibodies only resulted in 56% prevention.

• Journal of Embryo Transfer
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• v.18 no.2
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• pp.97-108
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• 2003

In-vitro fertilized Hanwoo embryos were biopsied for sex determination by PCR. Biopsied embryos were incubated for 1∼2 hours for the recovery. Those sexed Hanwoo embryos were transferred to 49 Hanwoo and 16 Holstein recipients from February 2000 to February 2001. Of 65 recipients, 14 cows(12 Hanwoo and 2 Holstein) delivered the same offspring as sex-determined by PCR, therefore the conception rate was 21.5%. 1. Total 65 embryos(male 35, female 30) were transferred to recipients, and 14 calves (male 6, female 8) were delivered. In comparison between sex by PCR method and sex of calves born after embryo transfer, the accuracy of sex determination was 100.0%. 2. The conception rate after transfer with biopsied embryo between Hanwoo and Holstein was 24.5% and 12.5% 3. The conception rate after transfer with biopsied embryo between fresh and frozen-thawed embryos was 23.5% and 14.3%. 4. The conception rate according to the season when embryo was transferred was 11.8, 29.4, 23.5 and 20.0% for spring, summer, autumn and winter, respectively. 5. The conception rate according to embryo quality after biopsy was 41.7, 30.0 and 0.0% for excellent, good and fair quality. 6. The conception rate according to thickness of uterine horn was 71.4, 18.9, 11.8 and 0.0% for 0, +, ++ and +++ thickness. 7. The conception rate according to the site in the uterine hem where embryo was put was 30.0, 20.0 and 10.0% for cranial, mid, and caudal part of uterine horn. 8. The conception rate according to the quality of corpus luteum ipsilateral to the uterine horn where embryos was transferred was 41.2, 14.3 and 15.4% for excellent, good and fair quality. 9. The conception rate according to the time required for embryo transfer was 18.2, 30.0, 30.0, 0.0 and 25.0% for 10, 15, 20, 25 and 30 minutes. 10. The conception rate according to parity of recipients was 26.5, 19.1, 14.3 and 0.0% for the primiparous, the 2nd parous, the 3rd parous and the 4th parous recipients. These results indicated that fresh embryos are more demanded than frozen-thawed embryos for good conception rate in embryo transfer with biopsied-sexed embryo. Also, it was indicated that we should consider embryo-recovering condition, recipient's uterine thickness, transfer site in uterine horn, quality of corpus luteum, time required for transfer and parity of recipient to achieve good conception rate in ET with biopsied-sexed embryos.

• Journal of Embryo Transfer
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• v.21 no.4
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• pp.299-306
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• 2006

This study examined the effects of the in vitro produced (IVP) Hanwoo blastocyst stage (blastocyst, expanded blastocyst and hatched blastocyst), in vitro culture day (7, 8, and 9) and blastocyst grade (1, 2 and 3) on the pregnancy rate, gestation length, birth weight, the incidence of dystocia and twining rate after embryo transfer (ET). The pregnancy and abortion rates were significantly higher in the blastocyst (B) stage (64.4%) and in the hatched blastocyst (HB) stage (21.4%), respectively, than in those of the other developmental stages (p<0.05). The pregnancy rate of Day 7 embryos (49.0%) was significantly higher than those of Days 8 and 9 embryos (36.4 and 15.4%), but the abortion rates were similar (0 to 10.7%). There were no significant differences in the pregnancy (41.4 to 42.5%) and abortion (9.3 to 16.5%) rates among the three grades of embryos. There were no significant differences in gestation length, birth weight and the incidence of dystocia among the three development stages, but the twinning rate was significantly higher in the HB stage (p<0.05). The pregnancy rate, the incidence rate of dystocia and twinning rate were similar among the three different culture days, however birth weight was significantly heavier in calves from Day 9 embryos than in those from Days 7 and 8 embryos. The mean gestation length of grades 1 and 2 embryos (278.5 and 276.1 days) were significantly longer than that of grade 3 (p<0.05), but birth weight, the incidence of dystocia and twinning rate did not significantly differ. The mean gestation length in single calves was significantly longer than that in twin calves (278.5 vs. 272.5 days, p<0.05). In addition, the mean birth weight in single calves was significantly greater than that in twin calves (29.6 vs. 22.3 kg, p<0.05). Finally, the sex ratios and mean mortality rates between single and twin calves were similar.